Effects of chronic aerobic exercise on attentional bias among women with methamphetamine addiction

Objective

To explore the effects of chronic exercise on attentional bias toward drug-related stimuli and on brain electrophysiological characteristics among women with methamphetamine addiction.

Methods

In total, 63 women with methamphetamine addiction were randomized to participate in a dance (n = 21; mean age, 32.16 ± 2.07 years), bicycle (n = 21; mean age, 32.59 ± 2.12 years), or control (maintained regular activities with little exercise; n = 21; mean age, 30.95 ± 2.81 years) group for 12 weeks. The participants in the three groups were not significantly different in terms of methamphetamine use or detoxification. Before and after the intervention, attentional bias was assessed using the dot-probe task, and event-related potentials were recorded during the task.

Results

The mean attentional bias scores decreased significantly after the intervention in both exercise groups but not in the control group. After 12 weeks of dance exercise, the amplitudes of the N170, N2, P2, and P3 components of the event-related potentials decreased significantly during attentional bias processing. In addition, differences in N170 amplitudes for congruent vs. incongruent conditions in the dot-probe task were no longer observed. After 12 weeks of cycling exercise, N2 and P2 amplitudes decreased significantly. By contrast, there were no significant differences in N170, N2, P2, and P3 amplitudes in the control group before vs. after the intervention.

Conclusions

Chronic (12 weeks of) aerobic exercise reduced attentional bias toward drug-related cues by improving attentional inhibition and reducing the maintenance of extra attention to drug-related cues among women with methamphetamine addiction. Both dance and bicycle exercise improved the early recognition of drug-related cues, weakened the influence of the memory of previous drug use, and improved attentional bias behavior by strengthening attention control. Dance exercise, but not bicycling, also regulated emotional control and improved the attention selection process. These results provide theoretical and empirical evidence that chronic aerobic exercise may reduce the attentional bias toward drug-related cues to assist in the recovery of women with methamphetamine addiction.

Aerobic exercise alters DNA hydroxymethylation levels in an experimental rodent model of temporal lobe epilepsy

The therapeutic potential of aerobic exercise in mitigating seizures and cognitive issues in temporal lobe epilepsy (TLE) is recognized, yet the underlying mechanisms are not well understood. Using a rodent TLE model induced by Kainic acid (KA), we investigated the impact of a single bout of exercise (i.e., acute) or 4 weeks of aerobic exercise (i.e., chronic). Blood was processed for epilepsy-associated serum markers, and DNA methylation (DNAme), and hippocampal area CA3 was assessed for gene expression levels for DNAme-associated enzymes. While acute aerobic exercise did not alter serum Brain-Derived Neurotrophic Factor (BDNF) or Interleukin-6 (IL-6), chronic exercise resulted in an exercise-specific decrease in serum BDNF and an increase in serum IL-6 levels in epileptic rats. Additionally, whole blood DNAme levels, specifically 5-hydroxymethylcytosine (5-hmC), decreased in epileptic animals following chronic exercise. Hippocampal CA3 5-hmC levels and ten-eleven translocation protein (TET1) expression mirrored these changes. Furthermore, immunohistochemistry analysis revealed that most 5-hmC changes in response to chronic exercise were neuron-specific within area CA3 of the hippocampus. Together, these findings suggest that DNAme mechanisms in the rodent model of TLE are responsive to chronic aerobic exercise, with emphasis on neuronal 5-hmC DNAme in the epileptic hippocampus.

A systematic review of exercise modalities that reduce pro-inflammatory cytokines in humans and animals' models with mild cognitive impairment or dementia

PURPOSE

To investigate which type, frequency, duration, intensity, and volume of chronic exercise might more strongly reduce pro-inflammatory cytokines and enhance anti-inflammatory cytokines in human and animal models with Mild Cognitive Impairment (MCI) or dementia.

DESIGN

A systematic review.

DATA SOURCE

English-language search of 13 electronic databases: Web of Science, PubMed/Medline, Sport Discus, Scopus, Cochrane, Psych Net, Springer, ScienceDirect, Pascal & Francis, Sage journals, Pedro, Google Scholar, and Sage.

INCLUSION CRITERIA

(i) human and animal studies that included exercise, physical activity, or fitness training as an experimental intervention, (ii) studies that addressed MCI, dementia, or AD, (iii) studies that focused on measuring cytokines and/or other inflammatory and/or neuroinflammatory immune markers, (iii) studies that examined inflammatory indicators in blood, CSF (Cerebrospinal Fluid), and brain tissue.

RESULTS

Of the 1290 human and animal studies found, 38 were included for qualitative analysis, 11 human articles, 27 animal articles, and two articles addressing both human and animal protocols. In the animal model, physical exercise decreased pro-inflammatory markers in 70.8 % of the articles and anti-inflammatory cytokines: IL -4, IL -10, IL-4β, IL -10β, and TGF-β in 26 % of articles. Treadmill running, resistance exercise, and swimming exercise reduce pro-inflammatory cytokines and increase anti-inflammatory cytokines. In the human model, 53.9 % of items reduced pro-inflammatory proteins and 23 % increased anti-inflammatory proteins. Cycling exercise, multimodal, and resistance training effectively decreased pro-inflammatory cytokines.

CONCLUSION

In rodent animal models with AD phenotype, treadmill, swimming, and resistance training remain good interventions that can delay various mechanisms of dementia progression. In the human model, aerobic, multimodal, and resistance training are beneficial in both MCI and AD. Multimodal training of moderate to high intensity multimodal exercise is effective for MCI. Voluntary cycling training, moderate- or high-intensity aerobic exercise is effective in mild AD patients.

Chronic Running Exercise Regulates Cytotoxic Cell Functions and Zinc Transporter SLC39A10/ZIP10 Levels in Diabetic Rats

The aim of this study is to investigate how chronic running exercise affects ZIP10 levels in thymus and spleen tissue as well as immune parameters in diabetic rats. A total of 40 adult male Wistar rats were divided into 4 equal groups: group 1, control; group 2, exercise control; group 3, diabetes; group 4, diabetes + exercise. Diabetes was induced by injecting intraperitoneal streptozotocin (STZ) at a dose of 40 mg/kg twice with 24-h intervals to the animals in groups 3 and 4. The animals in group 2 and group 4 underwent exercise for 45 min on the rat treadmill for 4 weeks at 20 m/min. Twenty-four hours after the last running exercise, the animals were sacrificed under general anesthesia. Immunological parameters were determined by flow cytometric method; tissue ZIP 10 levels were determined by ELISA method. The diabetic group had the lowest natural killer (NK) and natural killer T (NKT) cells percentages. Chronic exercise partially improved NK and NKT cell percentages in diabetic rats. The diabetic group had the lowest ZIP10 levels in spleen and thymus tissue. ZIP10 values in spleen and thymus tissue of diabetes exercise group were significantly higher than diabetes group. The results of our study show that the impaired cytotoxic cell functions in diabetes are partially corrected with 4 weeks of chronic exercise, and that the suppressed ZIP 10 levels in diabetic rats are reversed by 4 weeks of chronic exercise.

Purinergic signaling as a new mechanism underlying physical exercise benefits: a narrative review

In the last years, it has become evident that both acute and chronic physical exercise trigger responses/adaptations in the purinergic signaling and these adaptations can be considered one important mechanism related to the exercise benefits for health improvement. Purinergic system is composed of enzymes (ectonucleotidases), receptors (P1 and P2 families), and molecules (ATP, ADP, adenosine) that are able to activate these receptors. These components are widely distributed in almost all cell types, and they respond/act in a specific manner depending on the exercise types and/or intensities as well as the cell type (organ/tissue analyzed). For example, while acute intense exercise can be associated with tissue damage, inflammation, and platelet aggregation, chronic exercise exerts anti-inflammatory and anti-aggregant effects, promoting health and/or treating diseases. All of these effects are dependent on the purinergic signaling. Thus, this review was designed to cover the aspects related to the relationship between physical exercise and purinergic signaling, with emphasis on the modulation of ectonucleotidases and receptors. Here, we discuss the impact of different exercise protocols as well as the differences between acute and chronic effects of exercise on the extracellular signaling exerted by purinergic system components. We also reinforce the concept that purinergic signaling must be understood/considered as a mechanism by which exercise exerts its effects.

Physical exercise, obesity, inflammation and neutrophil extracellular traps (NETs): a review with bioinformatics analysis

Neutrophil extracellular traps (NETs) represent an innate organism defense mechanism characterized by neutrophil release of intracellular material to capture any aggressor agent. Elevated NETs release is associated with increased inflammatory response and related diseases, such as obesity. Chronic physical training is one of the main strategies to treat and prevent obesity. The relationship between physical training and NETs is still under study. The present review, followed by a bioinformatics analysis, demonstrates the meaningful connection between physical exercise, obesity, and NETs. The bioinformatics indicated TNF-α as a leading gene after the ontological analysis followed by positive-interleukin-6 regulation, chemokines, and inflammatory response regulation. The main results pointed to a relevant regulatory effect of physical training on NETs release, indicating physical exercise as a possible therapeutic target on modulating NETs and inflammation.

Exercise and Athletic Activity in Atrial Fibrillation

Moderate-intensity exercise improves cardiovascular outcomes. However, mounting clinical evidence demonstrates that long-term, high-intensity endurance training predisposes male and veteran athletes to an increased risk of atrial fibrillation (AF), a risk that is not observed across both genders. Although increased mortality associated with AF in the general population is not shared by athletes, clinically significant morbidities exist (eg, reduced exercise capacity, athletic performance, and quality of life). Additional research is needed to fill current gaps in knowledge pertaining to the natural history, pathophysiologic mechanisms, and management strategies of AF in the athlete.

Urinary Markers and Chronic Effect of Physical Exercise

Chronic kidney disease (CKD) is a type of kidney disease in which there is gradual loss of kidney function over a period of months to years. The clinical protocol of CKD forecasts that markers such as serum creatinine, the estimate of the glomerular filtration rate value, microalbuminuria, cystatin c are evaluated as routine markers. In recent years, new studies have identified new markers to diagnose and assess the level of kidney damage.The prevalence of CKD increases in subjects suffering from cardiovascular and metabolic diseases. The highest risk of cardiovascular risk in the CKD patient compared to the general population is related to risk factors such as hypertension, obesity, and specific renal disease factors such as albuminuria.Physical exercise, especially aerobic, has been seen through the analysis of urinary markers, able to mitigate the adverse effect of sedentary, hypertension and interstitial damage in patients with CKD and decrease the urinary levels liver-type fatty acid binding protein (L-FABP) and lower urinary albumin excretion.

A multidisciplinary weight loss intervention in obese adolescents with and without sleep-disordered breathing improves cardiometabolic health, whether SDB was normalized or not

OBJECTIVES

Pediatric obesity and sleep-disordered breathing (SDB) are strongly associated, and both promote metabolic impairments. However, the effects of a lifestyle intervention on the overall metabolic syndrome (MetS) are unknown. The objectives were i) to evaluate the effects of a lifestyle intervention on cardiometabolic risk (CMR), assessed with a dichotomous (MetS) and a continuous (MetScore_FM) instrument, in obese adolescents with and without SDB and ii) to compare the post-intervention cardiometabolic responses between adolescents with persistent (apnea-hypopnea index; AHI≥2) or normalized-SDB (AHI<2).

METHODS

Seventy-six adolescents with obesity recruited from two specialized institutions underwent a 9-12month diet and exercise intervention. Sleep and SDB (AHI≥2) were studied by polysomnography. Anthropometric parameters, fat mass (FM), glucose, insulin, lipid and leptin profiles, blood pressure (BP), MetScore_FM and MetS were assessed pre- and post-intervention. We performed comparisons between Non-SDB and SDB groups and between Normalized-SDB and Persistent-SDB subgroups.

RESULTS

Fifty participants completed the study. Pre-intervention, twenty youth had SDB (40%) with higher insulin concentrations and systolic BP than Non-SDB participants (p < 0.01), for a similar degree of obesity. Post-intervention, MetScore_FM (p < 0.001) and MetS prevalence (p < 0.05) were decreased in both groups. Eleven participants (55%) normalized SDB along with a decrease in insulin concentrations and BP (p < 0.05). Triglycerides, total cholesterol and LDL-cholesterol concentrations (p < 0.01) improved equally in the Normalized and Persistent-SDB subgroups.

CONCLUSION

SDB was associated with lower insulin sensitivity and higher BP but did not affect the lipid profile. A diet and exercise lifestyle intervention is effective in decreasing the CMR whether or not SDB was normalized in obese adolescents.

Effect of chronic exercise in healthy young male adults: a metabolomic analysis

AIMS

To examine the metabolic adaptation to an 80-day exercise intervention in healthy young male adults where lifestyle factors such as diet, sleep, and physical activities are controlled.

METHODS AND RESULTS

This study involved cross-sectional analysis before and after an 80-day aerobic and strength exercise intervention in 52 young, adult, male, newly enlisted soldiers in 2015. Plasma metabolomic analyses were performed using liquid chromatography, tandem mass spectrometry. Data analyses were performed between March and August 2019. We analysed changes in metabolomic profiles at the end of an 80-day exercise intervention compared to baseline, and the association of metabolite changes with changes in clinical parameters. Global metabolism was dramatically shifted after the exercise training programme. Fatty acids and ketone body substrates, key fuels used by exercising muscle, were dramatically decreased in plasma in response to increased aerobic fitness. There were highly significant changes across many classes of metabolic substrates including lipids, ketone bodies, arginine metabolites, endocannabinoids, nucleotides, markers of proteolysis, products of fatty acid oxidation, microbiome-derived metabolites, markers of redox stress, and substrates of coagulation. For statistical analyses, a paired t-test was used and Bonferroni-adjusted P-value of <0.0004 was considered to be statistically significant. The metabolite dimethylguanidino valeric acid (DMGV) (recently shown to predict lack of metabolic response to exercise) tracked maladaptive metabolic changes to exercise; those with increases in DMGV levels had increases in several cardiovascular risk factors; changes in DMGV levels were significantly positively correlated with increases in body fat (P = 0.049), total and LDL cholesterol (P = 0.003 and P = 0.007), and systolic blood pressure (P = 0.006). This study was approved by the Departments of Defence and Veterans' Affairs Human Research Ethics Committee and written informed consent was obtained from each subject.

CONCLUSION

For the first time, the true magnitude and extent of metabolic adaptation to chronic exercise training are revealed in this carefully designed study, which can be leveraged for novel therapeutic strategies in cardiometabolic disease. Extending the recent report of DMGV's predictive utility in sedentary, overweight individuals, we found that it is also a useful marker of poor metabolic response to exercise in young, healthy, fit males.

Effects of repeated voluntary or forced exercise on brainstem serotonergic systems in rats

Voluntary exercise increases stress resistance by modulating stress-responsive neurocircuitry, including brainstem serotonergic systems. However, it remains unknown how exercise produces adaptations to serotonergic systems. Recruitment of serotonergic systems during repeated, daily exercise could contribute to the adaptations in serotonergic systems following exercise, but whether repeated voluntary exercise recruits serotonergic systems is unknown. In this study, we investigated the effects of six weeks of voluntary or forced exercise on rat brain serotonergic systems. Specifically, we analyzed c-Fos and FosB/ΔFosB as markers of acute and chronic cellular activation, respectively, in combination with tryptophan hydroxylase, a marker of serotonergic neurons, within subregions of the dorsal raphe nucleus using immunohistochemical staining. Compared to sedentary controls, rats exposed to repeated forced exercise, but not repeated voluntary exercise, displayed decreased c-Fos expression in serotonergic neurons in the rostral dorsal portion of the dorsal raphe nucleus (DRD) and increased c-Fos expression in serotonergic neurons in the caudal DR (DRC), and interfascicular part of the dorsal raphe nucleus (DRI) during the active phase of the diurnal activity rhythm. Similarly, increases in c-Fos expression in serotonergic neurons in the DRC, DRI, and ventral portion of the dorsal raphe nucleus (DRV) were observed in rats exposed to repeated forced exercise, compared to rats exposed to repeated voluntary exercise. Six weeks of forced exercise, relative to the sedentary control condition, also increased FosB/ΔFosB expression in DRD, DRI, and DRV serotonergic neurons. While both voluntary and forced exercise increase stress resistance, these results suggest that repeated forced exercise, but not repeated voluntary exercise, increases activation of DRI serotonergic neurons, an effect that may contribute to the stress resistance effects of forced exercise. These results also suggest that mechanisms of exercise-induced stress resistance may differ depending on the controllability of the exercise.

Exercise and Doxorubicin Treatment Modulate Cardiac Mitochondrial Quality Control Signaling

The cross-tolerance effect of exercise against heart mitochondrial-mediated quality control, remodeling and death-related mechanisms associated with sub-chronic Doxorubicin (DOX) treatment is yet unknown. We therefore analyzed the effects of two distinct chronic exercise models (endurance treadmill training-TM and voluntary free wheel activity-FW) performed during the course of the sub-chronic DOX treatment on mitochondrial susceptibility to permeability transition pore (mPTP), apoptotic and autophagic signaling and mitochondrial dynamics. Male Sprague-Dawley rats were divided into six groups (n = 6 per group): saline sedentary (SAL + SED), SAL + TM (12-weeks treadmill), SAL + FW (12-weeks voluntary free-wheel), DOX + SED [7-weeks sub-chronic DOX treatment (2 mg kg^-1 week^-1)], DOX + TM and DOX + FW. Apoptotic signaling and mPTP regulation were followed by measuring caspase 3, 8 and 9 activities, Bax, Bcl2, CypD, ANT, and cophilin expression. Mitochondrial dynamics (Mfn1, Mfn2, OPA1 and DRP1) and auto(mito)phagy (LC3, Beclin1, Pink1, Parkin and p62)-related proteins were semi-quantified. DOX treatment results in augmented mPTP susceptibility and apoptotic signaling (caspases 3, 8 and 9 and Bax/Bcl2 ratio). Moreover, DOX decreased the expression of fusion-related proteins (Mfn1, Mfn2, OPA1), increased DRP1 and the activation of auto(mito)phagy signaling. TM and FW prevented DOX-increased mPTP susceptibility and apoptotic signaling, alterations in mitochondrial dynamics and inhibits DOX-induced increases in auto(mito)phagy signaling. Collectively, our results suggest that both used chronic exercise models performed before and during the course of sub-chronic DOX treatment limit cardiac mitochondrial-driven apoptotic signaling and regulate alterations in mitochondrial dynamics and auto(mito)phagy in DOX-treated animals.

Circulating Cell-Free DNA in Physical Activities

The interest about circulating cell-free DNA (cfDNA) concentration increased from several years because of its correlation with various conditions like osteoarthritis, cancers, stroke, and sepsis; recently it has become an important marker for overtraining syndrome or performance diagnostics.Several studies have demonstrated that cfDNA increases in vigorous and exhausting exercise but also endurance exercise. Acute effect of exercise on cfDNA concentration seems to be correlated to stress factor, while chronic effect is associated with necrosis and apoptosis.The intensity and duration seem to have effects on the variation of cfDNA concentration that is strongly correlated with other metabolic markers like acid lactate and creatine kinase, recognized as markers of muscle damage. Variation of cfDNA value could be used to predict overtraining syndrome.

Effect of a long-term treatment with metformin in dystrophic mdx mice: A reconsideration of its potential clinical interest in Duchenne muscular dystrophy

The pharmacological stimulation of AMP-activated protein kinase (AMPK) via metabolic enhancers has been proposed as potential therapeutic strategy for Duchenne muscular dystrophy (DMD). Metformin, a widely-prescribed anti-hyperglycemic drug which activates AMPK via mitochondrial respiratory chain, has been recently tested in DMD patients in synergy with nitric oxide (NO)-precursors, with encouraging results. However, preclinical data supporting the use of metformin in DMD are still poor, and its actions on skeletal muscle appear controversial. Therefore, we investigated the effects of a long-term treatment with metformin (200 mg/kg/day in drinking water, for 20 weeks) in the exercised mdx mouse model, characterized by a severe mechanical-metabolic maladaptation. Metformin significantly ameliorated histopathology in mdx gastrocnemius muscle, in parallel reducing TGF-β1 with a recovery score (r.s) of 106%; this was accompanied by a decreased plasma matrix-metalloproteinase-9 (r.s. 43%). In addition, metformin significantly increased mdx diaphragm twitch and tetanic tension ex vivo (r.s. 44% and 36%, respectively), in spite of minor effects on in vivo weakness. However, no clear protective actions on dystrophic muscle metabolism were observed, as shown by the poor metformin effect on AMPK activation measured by western blot, on the expression of mechanical-metabolic response genes analyzed by qPCR, and by the lack of fast-to-slow fiber-type-shift assessed by SDH staining in tibialis anterior muscle. Similar results were obtained in the milder phenotype of sedentary mdx mice. The lack of metabolic effects could be, at least partly, due to metformin inability to increase low mdx muscle levels of l-arginine, l-citrulline and taurine, found by HPLC. Our findings encourage to explore alternative, metabolism-independent mechanisms of action to differently repurpose metformin in DMD, supporting its therapeutic combination with NO-sources.

Leptin-induced basal Akt phosphorylation and its implication in exercise-mediated improvement of insulin sensitivity

Physical exercise is an efficient therapeutical tool in the management of insulin resistance (IR) and related metabolic diseases. Leptin, the well-known obesity hormone and the absence of which leads to IR, showed controversial effects on IR as research continues. Thus, in this study, a detailed investigation of the effect of leptin on exercise-mediated improvement of insulin sensitivity and its underlying mechanism was carried out. Using a rat model of chronic or acute swimming exercise training, we found that serum leptin increased 1 h after either acute exercise or the last session of chronic exercise, when impaired insulin action was observed in previous reports. However, chronic exercise reducd basal serum leptin levels and promoted insulin sensitivity compared with sedentary controls or rats subjected to one bout of aerobic exercise. Our animal results indicated the potential linkage between leptin and insulin sensitivity, which is further investigated in the skeletal muscle L6 cells. Leptin treatment in L6 cells promoted the basal levels of insulin signaling as well as glucose uptake, while blocking JAK2 signaling with either pharmacological intervention (JAK2 inhibitor AG490) or genetic manipulation (siRNA knockdown) decreased the basal levels of insulin signaling. Furthermore, leptin treatment inhibited insulin-stimulated insulin signaling and glucose uptake, while blocking JAK2 signaling restored leptin-attenuated insulin sensitivity. Taken together, our results demonstrated that reduced serum leptin, at least in part, contributes to exercise-mediated improvement of insulin sensitivity, indicating JAK2 as a potent therapeutical target of insulin resistance.

Examination of levels pentraxin-3, interleukin-6, and C-reactive protein in rat model acute and chronic exercise

Different types of exercise occurs damage at the cellular level in the muscles. Muscle damage caused by exercise is determined creatine kinase, myoglobin, and increase in levels of acute phase protein and interleukin in blood. The purpose of this study was investigated the levels of pentraxin-3 (PTX-3), interleukin-6 (IL-6), and C-reactive protein (CRP) following acute and chronic exercising in rats. Twenty-six Wistar Albino male rats were divided in to three groups. A treadmill exercise was performed 3 days/week, 10 min/day for 1 week in acute groups. In chronic group, exercise performed 7 days/week, 60 min/day for 4 weeks. At the end of the experiment, plasma PTX-3, IL-6, and CRP levels were measured. In current study, the PTX-3, IL-6, and CRP levels not observed statistically significant difference among control, acute, and chronic groups. The levels IL-6 and CRP were not significantly different between acute and chronic exercise groups (P>0.05). However, the level of PTX-3 was found to be higher in the chronic group compared to the acute group (P<0.05). The PTX-3 level increase on chronic exercise-induced muscle damage. Accorting to our results, we think that PTX-3 may have a protect role on muscle damage during chronic exercises.

Exercise and the Regulation of Immune Functions

Exercise has a profound effect on the normal functioning of the immune system. It is generally accepted that prolonged periods of intensive exercise training can depress immunity, while regular moderate intensity exercise is beneficial. Single bouts of exercise evoke a striking leukocytosis and a redistribution of effector cells between the blood compartment and the lymphoid and peripheral tissues, a response that is mediated by increased hemodynamics and the release of catecholamines and glucocorticoids following the activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. Single bouts of prolonged exercise may impair T-cell, NK-cell, and neutrophil function, alter the Type I and Type II cytokine balance, and blunt immune responses to primary and recall antigens in vivo. Elite athletes frequently report symptoms associated with upper respiratory tract infections (URTI) during periods of heavy training and competition that may be due to alterations in mucosal immunity, particularly reductions in secretory immunoglobulin A. In contrast, single bouts of moderate intensity exercise are "immuno-enhancing" and have been used to effectively increase vaccine responses in "at-risk" patients. Improvements in immunity due to regular exercise of moderate intensity may be due to reductions in inflammation, maintenance of thymic mass, alterations in the composition of "older" and "younger" immune cells, enhanced immunosurveillance, and/or the amelioration of psychological stress. Indeed, exercise is a powerful behavioral intervention that has the potential to improve immune and health outcomes in the elderly, the obese, and patients living with cancer and chronic viral infections such as HIV.

Exercise efficiency relates with mitochondrial content and function in older adults

Chronic aerobic exercise has been shown to increase exercise efficiency, thus allowing less energy expenditure for a similar amount of work. The extent to which skeletal muscle mitochondria play a role in this is not fully understood, particularly in an elderly population. The purpose of this study was to determine the relationship of exercise efficiency with mitochondrial content and function. We hypothesized that the greater the mitochondrial content and/or function, the greater would be the efficiencies. Thirty-eight sedentary (S, n = 23, 10F/13M) or athletic (A, n = 15, 6F/9M) older adults (66.8 ± 0.8 years) participated in this cross sectional study. O_2peak was measured with a cycle ergometer graded exercise protocol (GXT). Gross efficiency (GE, %) and net efficiency (NE, %) were estimated during a 1-h submaximal test (55% O_2peak). Delta efficiency (DE, %) was calculated from the GXT. Mitochondrial function was measured as ATP_max (mmol/L/s) during a PCr recovery protocol with ³¹P-MR spectroscopy. Muscle biopsies were acquired for determination of mitochondrial volume density (MitoVd, %). Efficiencies were 17% (GE), 14% (NE), and 16% (DE) higher in A than S. MitoVD was 29% higher in A and ATP_max was 24% higher in A than in S. All efficiencies positively correlated with both ATP_max and MitoVd. Chronically trained older individuals had greater mitochondrial content and function, as well as greater exercise efficiencies. GE, NE, and DE were related to both mitochondrial content and function. This suggests a possible role of mitochondria in improving exercise efficiency in elderly athletic populations and allowing conservation of energy at moderate workloads.

Effect of exercise-based cardiac rehabilitation on arterial stiffness and inflammatory and endothelial dysfunction biomarkers: a randomized controlled trial of myocardial infarction patients

BACKGROUND

Arterial stiffness have shown an independent predictive value for cardiovascular and all-cause mortality.

OBJECTIVE

This study sought to evaluate the effects of an 8-week exercise-based cardiac rehabilitation program (ECR) on arterial stiffness, and on inflammatory and endothelial dysfunction biomarkers. Additionally, it was assessed two potential confounding variables, daily physical activity and dietary intake.

METHODS

In this parallel-group trial, 96 patients (56 ± 10 years) were randomized to either the exercise group (EG) or control group (CG) 4 weeks after suffering acute myocardial infarction (MI). ECR consisted of 8 weeks of aerobic exercise at 70-85% of maximal heart rate during 3 sessions weekly, plus usual care. CG participants received only usual care. Baseline and final assessments included arterial stiffness through carotid-femoral pulse wave velocity (cf-PWV), inflammatory and endothelial dysfunction biomarkers, daily physical activity, and dietary intake. (ClinicalTrials.gov: NCT01432639).

RESULTS

After 8 weeks, no significant changes were found between groups in cf-PWV, inflammatory and endothelial dysfunction biomarkers, daily physical activity, or dietary intake. Excluding those patients (n = 7) who did not attend, at least 80% of the exercise sessions provided similar results, excepting a significant reduction in cf-PWV in the EG compared to the CG.

CONCLUSIONS

A short-term ECR does not seem to reduce arterial stiffness and inflammatory and endothelial dysfunction biomarkers of post-MI patients under optimized medication. Nevertheless, the decrease of cf-PWV observed in the EG, when considering only those patients who attended at least 80% of exercise sessions, warrants further investigation.

Influence of chronic exercise on red cell antioxidant defense, plasma malondialdehyde and total antioxidant capacity in hypercholesterolemic rabbits

Despite the knowledge on the antiatherogenic effects of exercise, the mechanism by which exercise reduces atherogenic risk remains unknown. In this study, we investigated the hypothesis that chronic exercise-induced oxidative stress may increase plasma total antioxidant capacity and antioxidant defense in the red cells. For 8 weeks, 60 male Dutch rabbits were fed rabbit chow with or without the addition of 2% cholesterol. The animals were further divided into rest and exercise groups (n = 15 for each group). Animals in exercise groups ran on a rodent treadmill at 15 m/min for 10 to 60 minutes gradually for 5 days per week for a total of 8 weeks. At the end of experiments, blood samples were collected and glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) activities were determined in red blood cells. Total antioxidant capacity (TAC), malondialdehyde (MDA) and total thiol (T-SH) levels were measured in plasma. Thoracic aorta and carotid arteries were isolated for histological examination to evaluate atherosclerosis. Eight weeks of chronic exercise reduced atherogenic diet-induced atherosclerotic lesions in all the arteries studied, along with positive changes in cholesterol profile, especially increase of serum HDL-C level. Plasma MDA, TAC and T-SH concentrations were enhanced by exercise in both control and hypercholesterolemic diet groups. Erythrocyte catalase activity was significantly increased by chronic exercise (p < 0.05), whereas total SOD activity rose with exercise only in the control group. Surprisingly, GPX activity was significantly reduced (P < 0.05) in response to exercise in the control group and also in the high cholesterol diet group. Exercise is a useful tool for the prevention and regression of atherosclerosis which is evident by our findings of the enhancement of plasma TAC and positive change in serum cholesterol profile. However, the effect of exercise on red cell antioxidant activities is limited in the hypercholesterolemic animals compared to control animals, possibly in part because of alterations in the ability to adapt to exercise-induced oxidative stress in high cholesterol diet. Key PointsPlasma MDA, TAC and T-SH concentrations were enhanced by exercise in both control and high cholesterol diet groups.GPX activity was significantly reduced in response to exercise in the control group and also in the high cholesterol diet group.Eight weeks of chronic exercise reduced atherogenic diet-induced atherosclerotic lesions in all the arteries studied.